sedimentary

Yellow Jasper (Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to brownish-orange, Luster: Waxy to dull, Structure: Cryptocrystalline, Fracture: Conchoidal

Hardness: 6

Identified July 19, 2026More sedimentary →

Explore Yellow Jasper (Chert) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to brownish-orange, Luster: Waxy to dull, Structure: Cryptocrystalline, Fracture: Conchoidal

Formation & geological history

Formed from the accumulation of silica-rich microfossils or volcanic ash that undergoes lithification through pressure and heat, often colored by iron oxides (goethite/limonite).

Uses & applications

Used primarily in lapidary arts for cabochons, beads, and decorative carvings; also used as landscaping gravel or for ornamental display.

Geological facts

Jasper is an opaque variety of chalcedony. The yellow variety is specifically associated with the presence of iron hydroxides. It has been used for millennia by humans for both tools and spiritual amulets.

Field identification & locations

Identify by its waxy texture, opacity (it will not let light pass through like quartz), and its inability to be scratched by a steel knife. Commonly found in riverbeds and coastal areas worldwide.